Re: Group CGAffineTransform Animations?
Re: Group CGAffineTransform Animations?
- Subject: Re: Group CGAffineTransform Animations?
- From: WT <email@hidden>
- Date: Thu, 18 Jun 2009 00:24:18 +0200
On Jun 17, 2009, at 11:11 PM, WT wrote:
You're absolutely correct in general, but - if I'm not mistaken -
CGAffineTransform rotations and scalings already do their thing with
respect to the center of the view they're being applied to. In fact,
I tested that before writing my solution to the OP's problem. And
that is indeed the source of the problem. Rotations and scalings, as
implemented by CGAffineTransform, are with respect to the view's
center but translations are with respect to the view's origin.
Therefore, if you scale while you translate, the view's origin
changes and the translation is no longer being applied with the
correct offset.
To be honest, I'm a bit surprised that CGAffineTransform rotations
and scalings are already defined with respect to the center of the
view. There's still a part of my brain that thinks that that isn't
true, but my tests indicated otherwise.
Wagner
I must be really tired...
I don't often make absurd statements, but the more I think about what
I said above, the more embarrassed I feel because, despite of what my
tests indicated, what I said above doesn't make much sense. A
translation is a rigid operation and, as such, is not defined with
respect to any anchor point or axis. So, at the very least, the
sentence "translations are with respect to the view's origin" is
completely wrong.
I hope that tomorrow, with a fresh mind, I'll be able to understand
why my solution worked. It clearly did, but not for the reasons I
claimed above.
Wagner
_______________________________________________
Cocoa-dev mailing list (email@hidden)
Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden